Results of ring annuloplasty for mitral regurgitation due to cardiomyopathy

Abstract

Congratulations to the authors for this study [1]. But we want to put an emphasis on some points that—we think—should be taken into consideration by the authors. Mitral annular area (calculated from the data in Table 1 in the original text) decreased from 12 cm to a postoperative value of 2.2 cm. This made us to think that the left ventricular volume reduction originated from mitral annular shrinkage. In addition, we suggest that coronary revascularization and resynchronization therapy both contributed to improvement in postoperative left ventricular ejection fraction (EF). Derived from Table 2, asymmetric tethering of mitral leaflets is a statistically significant indicator of postoperative mitral regurgitation. This is thought to be due to deterioration of coaptation by annuloplasty ring (although only 18% of cases had tethering preoperatively). Anyway, none of the rings can guarantee where the leaflet edges will be at the end of systole. Our opinion is that repair of mitral regurgitation in case of cardiomyopathy requires new approaches because 16% of patients still possess moderate-to-severe mitral regurgitation postoperatively. The use of flexible rings instead of rigid ones would allow annular contraction, thus resulting in better EF.